This invention relates to cinematographic systems utilizing a programmable viewing apparatus by which an exposed photographc film strip contained in a multi-purpose cassette may be processed, viewed by projection and rewound, either entirely or for a selected film length for replay, without removal from the viewing apparatus. More particularly, it concerns a programmable viewing apparatus which includes a control circuit for precluding projection of the non-usable leading end portion of the film strip during the project cycle while ensuring projection of the usable portion of the film strip; at all other times a project cycle is initiated, particularly after rewind for instant replay.
Cinematographic systems employing a programmable viewing apparatus and multipurpose cassette containing a photographic film strip together with a supply of processing fluid so that the film strip may be exposed in a camera and subsequently processed and projected in the programmable viewing apparatus are the subject of several issued U.S. Patents and pending applications commonly assigned to the assignee of the present invention. For example, the U.S. Pat. No. 3,851,958, issued to Edwin H. Land on Dec. 3, 1974 described a multipurpose cassette, motion picture system while the U.S. Pat. No. 3,895,862, issued on July 22, 1975 to Joseph A. Stella et al, is directed to a cassette arrangement for the above-noted system. U.S. Pat. No. 3,771,862, issued to Edwin H. Land on Nov. 13, 1973, describes an automatic viewing apparatus with a replay control for manually interrupting the projection cycle at any point and rewinding the film for a predetermined time or film length and projecting the rewound portion.
A recent development of the viewing apparatus for such systems is exemplified by U.S. Pat. No. 4,118,737, issued Oct. 3, 1978 to Melvin T. Chambers et al. In such systems, after the film strip is exposed by mounting the cassette in a motion picture camera, the cassette is inserted into an automatic viewing apparatus capable of discerning the processed or unprocessed condition of the film strip and, in the latter case, initiating a processing mode of operation. During processing, the viewing apparatus operates to rewind the film strip from a cassette contained takeup spool back to a supply spool under a processor nozzle by which processing fluid is spread evenly over the emulsion side of the film strip.
During the projection cycle, the viewing apparatus operates to wind the film from the supply spool to the takeup spool until the end of the film strip is reached at which time the film drive system is automatically reversed to rewind the strip back onto the supply spool. An instant replay mode may be initiated when the viewing apparatus is in the project or rewind mode by manual depression of a replay button. If instant replay is selected when the viewing apparatus is in the project mode, the viewing apparatus will immediately cycle to the rewind mode and the film will rewind until the replay button is released, whereupon the viewing apparatus will cycle through an off position to the project mode. If the replay button is depressed during rewind, the viewing apparatus will cycle through the off position to the project mode.
The foregoing and other modes of operation are described in detail in the aforenoted U.S. Pat. No. 4,118,737 which is hereby incorporated by reference. Briefly, the automated programming of diverse operating modes is effected by an integral programming disc in combination with electronic logic circuitry.
As is conventional, less than the entire length of the film strip is ever suitably exposed to result in useable frame images. For example, the leading end portion of the photographic film strip includes unwanted blank portions, projection of which is often distractive to the viewer. Heretofore, projection of the leading end portion has been precluded by providing a time delay to prevent operation of the projection lamp at the beginning of each forward projection cycle. Such a time delay, typically 7.5 seconds, is desired in commonly assigned application Ser. No. 791,036 filed Apr. 26, 1977, now abandoned.
The foregoing time delay thus prevents turn-on of the projection lamp at the commencement of each projection cycle. While such a time delay is effective to prevent projection of the non-useable leader portion of the film strip whenever projection of a fully rewound cassette is initiated, it disadvantageously delays projection for a predetermined time whenever projection of a less than fully rewound cassette is desired. Thus, whenever the replay mode of the viewer is selected to reproject a desired portion of the film strip, the time delay will inhibit the projector lamp turn-on after replay rewind for about 7.5 seconds at start of the projection cycle of the selected replay segment of the film strip.